US3780011A

US3780011A - Catalyst and catalytic process

Info

Publication number: US3780011A
Application number: US00132907A
Authority: US
Inventors: T Pullukat; M Shida
Original assignee: Chemplex Co
Current assignee: Enron Chemical Co
Priority date: 1971-04-09
Filing date: 1971-04-09
Publication date: 1973-12-18
Anticipated expiration: 1990-12-18
Also published as: CA994316A; DE2210959C2; JPS5410556B1; GB1334662A; IT952198B; DE2210959A1; FR2132707B1; BE780797A; NL7203110A; FR2132707A1

Abstract

A CATALYST CONTAINING CHROMIUM OXIDE SUPPORTED ON A DIFFICULTY REDUCIBLE CARRIER AS ITS MAJOR COMPONENT AND ALSO INCLUDING METAL OF THE CLASS CONSISTING OF TITANIUM, BORON, VANADIUM AND MIXTURES OF THESE IN WHICH THE CATALYST IS PARTICULARLY USEFUL FOR POLYMERIZING OLEFINS AND PARTICULARLY THOSE OF FROM 2 TO 8 CARBON ATOMS SO AS TO PREDETERMINE THE STRUCTURE, COMPOSITION, PHYSICAL AND CHEMICAL PROPERTIES AND USES AND APPLICATIONS OF THE RESULTING POLYMERS BY THE COMPONENTS OF THE CATALYST, WITH THE RESULT THAT THE POLYMER DESIRED IS PRODUCED IN THE REACTOR RATHER THAN BY POST-TREATMENT OF THE POLYMER OR BLENDING OF TWO OR MORE POLYMERS WITH DIFFERENT PROPERTIES IN AN ATTEMPT TO ACHIEVE A BLEND OF THE DESIRED PROPERTIES. THE DISCLOSURE ALSO INCLUDES THE METHOD OF POLYMERIZING AT LEAST ONE OLEFIN BY A PARTICLE FORM OR SLURRY PROCESS UTILIZING THE NEW CATALYST WITH THE POLYMERIZATION TAKING PLACE IN AN INERT DILUENT IN WHICH THE RESULTING POLYMER IS SUBSTANTIALLY INSOLUBLE AT THE TEMPERATURE AND PRESSURE OF POLYMERIZATION. THE NEW CATALYSTS CAN ALSO BE USED IN SOLUTION FORM POLYMERIZATION. THE CATALYST INCLUDES CHROMIUM OXIDE PLUS AN OXYGENATED METAL COMPOUND OF TITANIUM, BORON OR VANADIUM OR COMBINATIONS OF THESE. EXAMPLES OF SUCH CATALYSTS ARE CHROMIUM OXIDE PLUS TITANIUM, CHROMIUM OXIDE PLUS BORON, CHROMIUM OXIDE PLUS VANADIUM, CHROMIUM OXIDE PLUS TITANIUM AND BORON AND CHROMIUM OXIDE PLUS TITANIUM AND VANADIUM. IN EACH OF THESE THE TITANIUM, BORON AND VANADIUM ARE OXYGENATED AND PREFERABLY PREPARED BY TREATING THE ORGANIC COMPOUNDS, AND SPECIFICALLY ESTERS, OF THESE METALS WITH OXYGEN.

Description

'ABSTRACT OF THE DISCLOSURE .A catalyst containing chromium oxide supported on a difiicultly reducible carrier as its major component and also including metal of'the class consisting of titanium, boron, vanadium and mixtures of these in which the catalyst is particularly useful for polymerizing olefins and particularly those of from 2 to 8 carbon atoms so as to predetermine the structure, composition, physical and chemical properties, and uses and applications of the resulting polymers by the components of the catalyst, with the result that the polymer desired is produced in the reactor rather; than by post-treatment of the polymer or blending of two or more polymers with different proper- -ties in an attempt to achieve a 'blend of the desired properties. The disclosure also includes the method of polymerizing at least one olefin by av particle form or slurry process utilizing the'new catalyst with'the polymerization taking place in an inert diluent inwhich the resulting polymer is substantially insoluble at the temperature and pressure of polymerization. The new catalysts can also be used in solution form, polymerization.

.The catalyst includes chromium oxide plus an oxygenated metal compound of titanium, boron or vanadium or combinations of these. Examples of such catalysts are chromium oxide plus titanium, chromium oxide plus boron,-chromium-oxide plus vanadium, chromium oxide plus titanium and boron and chromium oxide plus titanium and vanadium. In each'of these the titanium, boron and vanadium are oxygenated and preferably prepared by treating then-organic compounds, and specifically esters, of these metals with oxygen.

1 The chromium'oxide catalyst polymerization of ethylene, for example, when conducted at low polymerizing temperature '(0;400 F. for bothparticle form and solutioii'form-polymerization) of-which about 200-290" F. is an exemplary range and low pressure (not over 1,000 p.s.i.l gauge) produces nearly 100% conversion of the ethylene; to high density polyethylene which is ordinarily defined as one having a density of 0.9'45to0.9 65 Such a polymer is crystalline, that is, relatively "unbranched and his inert to most chemicals, is rigid with good tensile strength an'd is usable at extremes of high and low temperatures without degr'adation'of physical" and chemical properties. Such a high density polyethyleneis essentially a chain of methyl? ene groups having a methyl group on one end and a vinyl group'on the other witha molecular weight of about U 70 temperature to prepare the catalyst for the polymerization 5,0'001'0 1,000,000. k I l A chromium 'oxide catalyst is activated at an elevated reaction. Preferably, this activation is done under non- States Patent v tionto i In addin' titanium; boron, vanadium orcombinations Patented Dec. 18, 19 73.

reducing conditions as in an atmosphere such as oxygen,

air, nitrogen, carbon dioxide or an inert gas constituent of air. The atmosphere is substantially anhydrous as by having a dew point below about 0 F. Reducing gases can ice , be present so long as the time of contact is limited to prevent substantial reduction of the hexavalent chromium content.

r The temperature and time of activation can vary over wide ranges, but the activation temperature will ordinarily be from about 350-1800 F. with a practically desirable. range being about 750-1650 F. for times varying, for.

The chromium oxide process of polymerizing l -olefinsis particularly adaptable to the particle form or slurry process in which the polymer formed is insoluble in the liquid present at the low temperatures and low pressures.

used. This particle form process results in polymers with higher molecular weights. The essential ingredients in such a customary particle form process are the diluent liquid which is usually a hydrocarbon, the olefin and the catalyst suspended in the liquid. The polymer that is" formed also remains predominantly suspended in the liquid along with the catalyst so that it may be easily separated with the catalyst from the liquid. If desired,;

the polymer and catalyst may be separated from each other by well-known processes or the catalyst may be left in thepolymer where the presence in such small amountswill not be harmful.

There are many materials which can be used as a support or carrier for active catalytic agents in the customary manner. The particular choice of a carrier depends upon many factors, e.g. surface area, density, porosity, particle size, specific heat, heat stability, and mechanical strength." Most carrier materials, and the naturally occurring ma-' terials in particular, are generally pretreated by washing,-

grinding, acid treating, calcining, or other means to re move impurities or to improve physical characteristics of the material. Carriers suitable for the catalyst of the present invention are diflicultly reducible materials, for example, silica gel, natural and synthetic alumina, mixed gels comprising SiO and A aluminum silicate, and pumice. The preferred carriers include silica, alumina, zirconia, thoria and mixed gels of which the dry matter comprises mainly, i.e. more than:

50% by weight, free and/or bound SiO; and (minor amounts of A1 0 Examples of mixed gels are the com; mercial silica-alumina cracking catalyst. The expression: gel is used to designate both the fresh, water-containing gelsfproper' and the "products obtained by drying (.actiVat-jf ing)=these gels. i H

- A-SUYMMARYI OF THE INVENTION h'aveinvented a class of catalysts that are improverr'ient sj cwer the commonly usedlcatalysts described gener ally in the above background. These cont'ain titanium,

boron, vanadium or mixtures in oxygenatedI'form in addie customaryphromitpn 0xide.

theorganic compounds of the metals are .mixedl together before addition to'the chromium'oxide catalyst which at that timema'y beonthe ,carrienThen the oxygen isintroduced oxygenate the compounds,..fIfhe catalysts of this invention" may be used "for both solution form" and particle form polymerization.

index (MI, which indicates generally the molecular v, weight) that is higher (as determined by ASTM Dl238- 52T), i.e. have a lower molecular weight, than heretofore obtained in particle form olefin, and particularly ethylene, polymerization systems, and a high and variable shear response or molecular weight distribution (MWD) as determined by the ratio of high load melt index (HLMI) to regular melt index (MI). The presence of the boron, vanadium or both results in polyolefins and particularly polyethylene of low shear response or HLMI to MI by ratio.

Thus the invention involves not only novel modified chromium oxide catalyst systems but also new methods of producing polyolefins and novel polyolefins having characteristics exactly tailored to the desired characteristics by controlling the amounts of titanium and/ or boron and/or vanadium that are present with the chromium oxide. For example, by using a mixture of chromium oxide with oxygenated titanium, boron, or vanadium, or combinations, a polyethylene is produced having a high MI resulting from the presence of the titanium combined with the narrow MWD resulting from the boron or vanadium or both.

The greatest use for high density polyethylene at the present time is in blow molding processes. For a high density polyethylene to have good characteristics for blow molding it must have somewhat specific viscoelastic properties'and the present particle form polymerization techniques are not flexible enough to produce high density polyethylene with the range of viscoelastic properties required particularly for blow molding the polyethylene with the common high speed reciprocating extruding processes and machines. At the present time polyethylene for blow molding is compounded by blending particle form and solution form high density polyethylenes in various proportions to achieve the desired resin properties.

Such blending of the two forms of polyethylene is not entirely satisfactory because it is difiicult to achieve the exact results required. Polymers made by this invention avoid these difiiculties as the catalyst of this invention can have predetermined properties by a suitable choice of constituents to produce high density polyethylene in the reactor directly usable for blow molding applications. Thus it is now possible with the catalyst of this invention to produce polyethylene resins with variable shear response in a particle form ethylene polymerization system. The catalysts of this invention can also be used for solution form polymerization.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The presence in the catalyst of the titanium with the chromium oxide results in a polyolefin, and particularly a polyethylene, of high melt index which is higher than that before obtainable in a particle form ethylene polymerization system using the customary chromium oxide catalyst. The presence of the titanium in the catalyst also results in an olefin polymer, particularly a polyethylene, of high and variable shear response or molecular weight distribution (MWD) as determined by the ratio of high load melt index (HLMI) to regular index (MI) [ASTM D-123 8-62T, conditions F and B, respectively].

The usual chromium oxide containing catalyst produces a polyethylene with limited control over molecular weight which makes it unsuitable for certain uses and.

particularly for injection molding. The new catalysts" of this invention avoid this.

In preparing the catalyst of this invention a catalyst support of thetypediscussed above (of which silicg'jis an excellent example) is mixedwith the desired propor tion of chromium trioxide and this mixture is thendried ,1 by fluidizing' at an elevated temperature in a catalyst activator using dry air or similar atmosphere also as dis? cussed above. Then to the fluidized of catalyst at the means reaction rate expressed drying temperature used, a titanium, for example, alkyl ester containing from 1 to 7 carbon atoms in the alkyl group is introduced. Thus an excellent ester has been found to be titanium tetraisopropionate and in specific examples was introduced in amounts of 2%, 2 /2 3%, 5% and 8% by weight of the catalyst. Examples of such esters are tetramethyl, tetrahexyl, the isomeric tetrapropyl, tetraethyl, tetrabutyl, tetraamyl and tetraheptyl.

Upon the addition of the titanium ester the orange catalyst turns grey and there is a sudden jump in temperature of as much as 60C. indicating an'exothermic reaction. This titanium treated catalyst is then activated at an even higher temperature using dry air. The final activated catalyst may then .be used in l-olefin, e.g. ethylene, polymerizations at polymerization temperatures and pressures. l

The treatment of the catalyst with titanium is normally carried out at the relative high temperature of approximately C. e

The optimum concentration of chromium trioxide in the catalyst of this invention is about 2%. For highest MI the optimum amount of titanium is about 3.5%. By varying the titanium concentration on the catalyst, the shear sensitivity of the resulting polymer can be varied as desired. The titanated catalysts of this invention are considerably more active than the standard catalyst and the polymerization reaction proceeds with no induction time.

The melting characteristics of polyethyleneproduced with the titanated catalyst of this invention are ditferent from the melting characteristics of regular particle form polyethylene. The molecular weight distribution by gel permeation chromatographytGPC) of the polyethylene produced with the titanated catalyst of this invention is similar to that of a solution form polyethylene.

By using controlled polymerization with catalysts not containing the titanium compounds'it is readily evident that the titanium treated-catalyst of this invention gives polyethylene resins with much'higher meltindexes than the untreated catalysts as shown on the following Tables I, II and III.

In some tests a chain transfer agent such as hydrogen, hexene and the like was used and further increased the melt index and the variable shear response. Silica having a large pore volume resulted in polyethylene of a higher melt index for a given titanium content in the catalyst. The shear response of the .polyethylene made by the titanium treated catalyst is higher than that obtained from a catalyst containing no titanium..Thus by varying the concentrations of the titanium in the catalyst it is possible to control the viscoelastic properties of the resulting polyfollowed.

Polymerizations were carried out in a 1300 ml. capacity chromium plated carbon steel reactor. The reactor was purged with nitrogen while it was maintained at 108 C. A 0.0793 g. quantity of the catalyst was charged into the reactor and the reactor was closed. 'Isobutane (500 ml.)

was charged into the reactor and stirring was started. Ethylene was admitted to maintain a pressure of 5 50 p.'s.i. gauge. After 100 minutes, the reactor was opened,

andfall the volatile components were evaporated. A yield or 180.4 g. of polymer-was obtained which amounts to a reactivity of 1365 g./g..cat./hr. The melt index of the.

product was 0.86 and the HLMI/MI ratio, was 47.3.

In. the tables herein, prod. -means production of polymer per unit weight (gram) of catalyst and react."

asgr-ams of polymer per gram of catalyst per hour.

index eifect of titanium ester and the narrow molecular weight distribution effect of boron ester. These results are In the catalyst of this invention the carrier is the major component. The chromium oxide present has a chromium content of about 0.5-10 weight percent of the catalyst, the oxygenated titaniumhas a"titanium content of about :5- 10 weight percent of the catalyst and the boron, vanadium illustrated in the accompanying Table VII. or both where used each hasasin ilar 0 5 weight per:

TABLE v11 Polymerization of Ethylene Using Silica-2% CrO; Containing 1.8% B and 2.5% Ti p.s.i.g.)

Length Rxn. React. Act. temp. Cat. wt. of run temp. Yield Prod. (fJg. Example No. 0.) (g-) (g-) (gJgcat.) cat. hr.) MI HLMI/MI "i V '7 V V 810 0680 80 108 142. 6 2, 100 1,570 1. I 810 .0573 108. 123.5 2,160 v. 1,630.17... TABLE VIII I Eflect o! Drying Temperature 0! Silica Beiore Titanium Treatment Davison, 952-292, CrOa, 3 5% Ti Catalyst I I Drying I Length Re act.- temp. Cat. wt.- of run Temp. Yield Prod. ./g. 7 Example N0. G.) (g.) (min.) F.) (g.) (g./g. cat.) cat. r.), H J HLMI/Mli 47 40 .0607 226 123.3 2,030 1, 32 @1 4.8 150 .0533 226 106.0 1,970 5. 4 x361) in by a nitrogen stream while the titanium compound was heated to its boiling point. The result is shown below.

cent content of the catalyst. These are expressed on the basis of the metal present. The polymerization tempera; tures, pressures, 'timesand other conditions ,ar l'a's'dis cussed above in the background of theinventiom,

All percentages'herein are-by weightifi .9.

TABLE IX Length React;-- Ti Cat. wt. of run Temp. Yield Prod. (};./g, Example No. (percent) (g-) (min.) F.) (g.) (gJg. cat.) 01mm. 1 HLMI/MI v Davison 969 MS catalyst (silica with 2% CrO was predried at 100 C. for 3 hours and used in place of 952-2% CrO The results are shown below:

Having described our invention as related to the em bodiments set out herein, itis our intention thatthe in- V vention be not limitedby any oi the details of descrip- TABLE X Length 7 Ti Cat. wt H: Tfinip. otrun Prod. React. (g./ Y HLMI/ Example No; (percent) (g) (p.s.i.) (min.) Yield (g) (g./g. cat.) g. cat.[h r.) 'MI 3. 5 0459 50 226 111. 2 2, 420 1, 715 I 6. 8 j 45. 4 3.5 .0648 0 208 50 151.3 2, 330 2,800 .11" 155.7 3. 5 0597 0 215 55 129. 0 360 27 v 126. 0 0 .0448 0 226 55 97.2 2, 2,370 88' 56. 2 2.5 .0708 0 226 70 128.0 1,810 1,550 2.25 f 56.0 2.5 .0469 0 226 75 101.0 2, 150 1,720 2.60 51.5 7.0 .0617 0 226 60 125.5 2,035 2,035..- 7. 0 0555 0 227 90 104. 9 1, 905 1, 274' 4. 97. 46. 3

In the hexene modification of titanium catalyst, 969 MS 5% titanium catalyst was used in hexene copolymerizations of ethylene. Hexene increases the MI and shear response of the copolymer. The results are shown below:

tion, unless otherwise specified, but rather be'construed broadly within its spirit and scope as set out in theappended claims. 1 3

' TABLE XI Length Cat.wt. Tenip. oirun Prod. Beact.(g.; HLMI/ can (g.) (m (g-) (aleat) -v tflhr- TL- .0523' 221 60 100.0 2 000 2090 159 =-fe15 U sum 2% croam .05 218.5 110 114.0 21001 11090 9.07 34.9

15 00.01 hexane was added. v I p m Tetrabutyl and'tetraethylhexyl' titanate were used in "We claim:-

place of tetraisopropyl titanate for titanation of 952-2% a catalyst e t o t es stsrsfi w a smaller than that of tetraisopropyl titanate, as shown on the following table. :1 1

65 1. A catalyst prepared by .first forming a substantially ""Tmiexnjjf 8 React.

. I or 111111 Temp. yield "Prod; 7 (g,/ HLMII Example No. (percent) Ester Cat.wt. (3.) (min.) F.) (3.) (g.lg;cat.)' 'catJhr. 1 1-; .0486 75 'f 220' 102.8 2,110 .5: 3 5%"... 70 126.6 2,170 5 8.5 Ethylhexyl .0501- 65 226 106.7 2,130 62.2

1 All catalysts were predried at 100 C. for 3 hourabeiore titanation. I

tially dry bed containing about -10 weight percent chromium including at least about 0.1 weight percent hexavalent chromium, followed by fluidizing said bed with a substantially dry gas, and then adding to said bed at. an el eyatedtemperature while fluidizing an alkyl ester of a memberof the class consisting of the metals titanium, boron, vanadium and combinations thereof containing 1 -97 carbon atoms in the alkyl group, said ester being substantiallyfree of non-aqueous solvents and said gas being substantially .inert to said bed ,and said ester, and acti- Vating said bed with a dry gas that contains oxygen, said ester, having been addedin an amount to give about 0.5- weight percent of said metal in the final catalyst.

2.'The catalyst of claim 1 wherein said bed is dried before, the adding of the ester by fluidizing the 'bed at an elevated drying temperature.

31 The catalyst of claim 2 wherein said ester is added tothe fluidized bed at the drying, temperature and said a'ctivating'of the bedis at a temperature above the drying temperature. p I

4. The catalyst of claim 1 wherein said ester is added to said fluidized bed so as to give about 3.5 weight percent of said metal in said catalyst.

5. The catalyst of claim 1 wherein said elevated temperature is approximately 100 C.

' 6. 'A catalyst prepared by first forming a substantially dry intimate mixture of a support'of the class consisting of 'silica, alumina, zirconia, thoria and mixtures thereof and chromium oxide on said support to form a substantially dry bed' containing about 05-10 weight percent chromium including at least about 0.1 weight percent hexavalent chromium, followed by fluidizing said bed with a-"substantially dry gas, and then adding to said bed at an elevated temperature while fiuidizing an alkyl ester of titanium containing 1-7 carbon atoms in the alkyl group, said ester being substantially free of non-aqueous solvents and said gas being substantially inert to said bed and said ester, and activating said bed with a dry gas that contains oxygen, said ester having been added in an amount to give about 05-10 weight percent of said titanium in the final catalyst.

7. Acatalyst prepared by first forming a substantially dry intimate mixture of a support of the class consisting of silica, alumina, zirconia, thoria and mixtures thereof and chromium oxide on said support to form a substantially dry bed containing about 05-10 weight percent chromium including at least about 0.1 weight percent hexavalent chromium, followed by fluidizing said bed with a substantially dry gas, and' then adding to said bed at an elevated temperature while'fiuidizing an alkyl ester of boron containing 1'7'c'a'rbon atoms in the alkyl group, said ester being substantially free of non-aqueous solvents and said gas being substantially inert to said bed and said ester, and activating "said bed with a dry gas that contains oxygen, said ester havingbeen added in an amountlto give about 0.5 10 weight percent of said boron in'the final catalyst. a.

catalyst prepared by, first forming a substantially dryhintimate mixturev of a support of the class consisting of Silica, alumina, zirconia,-thoria and mixtures thereof and chromium. oxide on said support to form a substantiaIIy-F-dry bed containing about 05-10 weight percent chromium including at least about 0.1 weight percent hexavalent chromium, followed by 'fluidizing said bed witha substantially dry gas, and-then addingto "said bed at an elevated temperature while fiuidizing an alkyl ester of titanium and an alkylester of boron each containing 1- -7 carbon ,atomsin the, alkyl group, said esters-being 9. The method of making polymers of controllable viscoelastic responses, narrow to broad molecular weight distribution, particularly suitable in blow molding, injection molding, thermoforming, film extrusion, and the like, from polymerizable l-olefins which comprises polymerizing at least one of said olefins under polymerizing conditions with a catalyst prepared by first forming a substantially dry intimate mixture of a support of the class consisting of silica, alumina, zirconia, thoria and mixtures thereof and chromium oxide on said support to form a substantially dry bed containing about 05-10 weight percent chromium including at least about 0.1 weight percent hexavalent chromium, followed by fluidizing said bed with a substantially dry gas, and then adding to said bed at an elevated temperature while fluidizing an alkyl ester of a member of the class consisting of the metals titanium, boron, vanadium and combinations thereof containing 1-7 carbon atoms in the alkyl group, said ester being substantially free of non-aqueous solvents and said gas being substantially inert to said bed and said ester, and activating said bed with a dry gas that contains oxygen, said ester having been added in an amount to give about 05-10 weight percent of said metal in the final catalyst and recovering a polymer.

10. The method of making polyethylene of controllable viscoelastic responses, narrow to broad molecular weight distribution, particularly suitable in blow molding, injection molding, thermoforming, film extrusion, and the like which comprises polymerizing ethylene under polymerizing conditions with a catalyst prepared by first forming a substantially dry intimate mixture of a support of the class consisting of silica, alumina, zirconia, thoria and mixtures thereof and chromium oxide on said support to form a substantially dry bed containing about 0.510 weight percent chromium including at least about 0.1 weight percent hexavalent chromium, followed by fluidizing said bed with a substantially dry gas, and then adding to said bed at an elevated temperature while fluidizing an alkyl ester of a member of the class consisting of the metals titanium, boron, vanadium and combinations thereof containing 1-7 carbon atoms in the alkyl group, said ester being substantially free of non-aqueous solvents and said gas being substantially inert to said bed and said ester, and activating said bed with a dry gas that contains oxygen, said ester having been added in an amount to give about 0.5-10 weight percent of said metal in the final catalyst and recovering polyethylene.

11. The method of making polymers of controllable viscoelastic responses, narrow to broad molecular weight distribution, particularly suitable in blow molding, injec tion molding, thermoforming, film extrusion and the like, from polymerizable l-olefins which comprises polymerizing at least one of said olefins under polymerizing conditions with a catalyst prepared by first forming a substantially dry intimate mixture of a support of the class consisting of silica, alumina, zirconia, thoria and mixtures thereof and chromium oxide on said support to form a substantially dry bed containing about 0.5-10 weight percent chromium including at least about 0.1 weight percent hexavalent chromium, followed by fluidizing said bed with a substantially dry gas, and then adding to said bed at an elevated temperature while fiuidizing an alkyl ester of titanium containing l-7 carbon atoms in the alkyl group, said ester being substantially free of non-aqueous solvents and said gas being substantially inert tosaid bed and Said ester, and activating said bed with a dry gas that contains oxygen, said ester having {been added in an amount to give about 05-10 weight percent of .said titanium in the final catalyst and recover-.

ing a polymer.

12. The method of making polymers of controllable viscoelastic responses, narrow to broad molecular weight distribution, particularly suitable in blow molding, injection molding, thermoforming, film extrusion, and the like, from polymerizable 1-olefins which comprises polymerizing at least one of said olefins under polymerizing conditions with a catalyst prepared by first forming a substantially dry intimate mixture of a support of the class consisting of silica, alumina, zirconia, thoria and mixtures thereof and chromium oxide on said support to form a substantially dry bed containing about 05-10 weight percent chromium including at least about 0.1 weight percent hexavalent chromium, followed by fiuidizing said bed with a substantially dry gas, and then adding to said bed at an elevated temperature while fluidizing an alkyl ester of boron containing 1-7 carbon atoms in the alkyl group, said ester being substantially free of nonaqueous solvents and said gas being substantially inert to said bed and said ester, and activating said bed with a dry gas that contains oxygen, said ester having been added in an amount to give about 05-10 weight percent of said boron in the final catalyst and recovering a polymer.

13. The method of making polymers of controllable viscoelastic responses, narrow to broad molecular weight distribution, particularly suitable in blow molding, injection molding, thermoforming, film extrusion, and the like, from polymerizable l-olefins which comprises polymerizing at least one of said olefins under polymerizing conditions with a catalyst prepared by first forming a substantially dry intimate mixture of a support of the class consisting of silica, alumina, zirconia, thoria and mixtures thereof and chromium oxide on said support to form a substantially dry bed containing about 0.5- weight percent chromium including at least about 0.1 weight percent hexavalent chromium, followed by fluidizing said bed with a substantially dry .gas, and then adding to said bed at an elevated temperature while fluidizing an alkyl ester of titanium and an alkyl ester of boron each containing 1-7 carbon atoms in the alkyl group, said esters being substantially free of non-aqueous solvents and said gas being substantially inert to said bed and said esters, and activating said bed with a dry gas that contains oxygen, said esters having been added in an amount to give about 0.510 weight percent of said titanium and boron in the final catalyst and recovering a polymer.

14. The method of making polyethylene of controllable viscoelastic responses, narrow to broad molecular weight distribution, particularly suitable in blow molding, injection molding, thermoforming, film extrusion, and the like which comprises polymerizing ethylene under polymerizing conditions with a catalyst prepared by first forming a substantially dry intimate mixture of a support of the class consisting of silica, alumina, zirconia, thoria and mixtures thereof and chromium oxide on said support to form a substantially dry bed containing about 05-10 weight percent chromium including at least about 0.1 weight percent hexavalent chromium, followed by fluidizing said bed with a substantially dry gas, and then adding to said bed at an elevated temperature while fluidizing an alkyl ester of titanium containing 1-7 carbon atoms in the alkyl group, said ester being substantially free of non-aqueous solvents and said gas being substantially inert to said bed and said ester, and activating said bed with a dry gas that contains oxygen, said ester having been added in an amount to give about 0.5-10 weight percent of said titanium in the final catalyst and recovering polyethylene.

15. The method of making polyethylene of controllable viscoelastic responses, narrow to broad molecular weight distribution, particularly suitable in blow molding, injection molding, thermoforming, film extrusion, and the like which comprises polymerizing ethylene under polymerizing conditions with a catalyst prepared by first forming a substantially dry intimate mixture of a support of the class consisting of silica, alumina, zirconia, ,thoria and mixtures thereof and'chromium'oxide on said support to form a substantially dry bed containing about.0.5 -'l0 weight percent chromium including at least about .0.1 weight percent hexavalent chromium, followed by fluidizing said bed with a' substantially dry gas, and then adding to said bed at an elevated temperature while' fluidizing an alkyl ester of boron containing 1-7, carbon atoms in the alkyl group, said'ester being substantially free of non-aqueous solvents and said gas being substantially inert to said bed and said ester, and activating said bed with a dry gas that contains oxygen, said ester having been added in an amount to give about 0.5-10 weight percent of said boron in the final catalyst and recovering polyethylene. i v 1' 16. The method of making polyethylene of controlla ble viscoelastic responses, narrow to broad ,molecular weight distribution, particularly suitable in blow molding, injection molding, thermoforming, film extrusion, and the like which comprises polymerizing ethylene'under polyms erizing conditions with a catalyst prepared by first forming a substantially dry intimate mixture of a support of the class consisting of silica, alumina, zirconia, thoria and mixtures thereof and chromium oxide on said support to form a substantially dry bed containing about 05-10 weight percent chromium including at least about 0.1

weight percent hexavalent chromium, followed by fluidizing said bed with a substantially dry gas, and then adding to said bed at an elevated temperature while fluidizing an alkyl ester of titanium and an alkyl ester of boron each containing 1-7 carbon atoms in. the alkyl group, said esters being substantially free of non-aqueous solvents and said gas being substantially inert to said bed andfsaid esters, and activating said bed with a, dry gas that contains oxygen, said esters having been added in an amount to give about 05-10 weight percent of said titanium and boron in the final catalyst and recovering polyethylene.

17. The catalyst of claim 1 wherein said member comprises vanadium.

18. The catalyst of claim 1 wherein said member comprises titanium and vanadium- 19. The catalyst of claim 1 wherein said member comprises titanium, boron and vanadium.

20. The method of claim 9 wherein said olefin comprises propylene. I

21. The method of claim 9. wherein said member comprises vanadium.

22. The method of claim 9 wherein said prises titanium and vanadium. V

23. The method of claim 9 wherein said member comprises titanium, boron and vanadium.

member com- References Cited UNITED STATES PATENTS 3,485,771 12/1969 Horvath 26094.9 D 3,484,428 12/1969 K'allenbach 260-'94.9 D 3,239,498 3/ 1966 Witt 26094'.9' D 3,349,067 10/1967 Hill 26094.9*'"D 2,898,326 8/ 1959' Peters et al. 252430 3,622,521 11/1971 Hogan et al. 260-94.9 D 3,625,864 12/ 1971 Horvath '..1 260-949 D 3,635,840 1/1972